1. Field of the Invention
The present invention relates to nanostructures and, more specifically, to arrays of vertically aligned nanostructures.
2. Description of the Related Art
ZnO nanowires (NW) are one-dimensional nanostructured building blocks that have been used in energy harvesting, sensing, optoelectronic and electronic applications. Assembly and integration of highly-ordered nanowire arrays at large scales is important for multi-functional devices and systems. Efforts have been made to assemble large quantity nanowires through two parallel processes: grow-and-place (GAP) and grow-in-place (GIP). The GAP approach includes alignment induced by dielectrophoresis and methods utilizing magnetic fields, as well as microfluidic, electrostatic, molecular, and shear forces. Although the GAP technique can be used to fabricate a finite number of devices, it is rather challenging to assemble the as-synthesized nanowires into desired configurations at large scale. In GIP technique, nanostructures grow in-situ at the patterned catalyst/seed sites created through lithography, such as electron beam lithography (EBL), nano-imprint lithography (NIL), and nano-sphere lithography (NSL). Control over the growth substrate can guide the size, placement, and orientation of the grown nanowires. Patterned growth of aligned ZnO nanowires has been achieved via the hydrothermal (HT) method and physical vapor deposition (PVD). However, none of the above approaches provides a reliable, high-throughput, and low-cost solution for large scale fabrication of patterned ZnO nanowire arrays at a level required for industrial applications.
Therefore, there is a need for a reliable, high-throughput, and low-cost method for large scale fabrication of patterned ZnO nanowire arrays